turtlebot3_core_extra_motors

This can control extra two motors in a turtlebot3 waffle.

Prerequisites

1. Computer

• Packages for turtlebot3 waffle should be installed.
• OpenCR 1.0, examples for turtlebot3 should be install in arduino ide.
• Dynamixel2Arduino library should be installed in arduino ide.

2. Dynamixel X series

• OpenCR must be connected to the computer using arduino ide when uploading this ino file.
• Dynamixel motors must be connected to OpenCR 1.0
• ID: wheel motors(1, 2), one extra motor (4), two extra motors (3, 4)
• baudrate: 1000000

3. LED

• LED must be connected to OpenCR 1.0
• communication: UART (no use SoftwareSerial)
• The number of LED is 4 (front, back, left, right of a robot)

File Structure

├── LICENSE
├── README.md
├── lib
│   └── motor_driver
│       └── oneExtraMotor
│           ├── turtlebot3_motor_driver.cpp
│           └── turtlebot3_motor_driver.h
├── oneExtraMotor
│   ├── positionMode
│   │   ├── turtlebot3_core.ino
│   │   ├── turtlebot3_core_config.h
│   │   └── turtlebot3_waffle.h
│   └── velocityMode
│       ├── turtlebot3_core.ino
│       ├── turtlebot3_core_config.h
│       └── turtlebot3_waffle.h
└── twoExtraMotors
    └── positionMode
        ├── customVelocity
        │   ├── turtlebot3_core.ino
        │   ├── turtlebot3_core_config.h
        │   └── turtlebot3_waffle.h
        └── syncVelocity
            ├── bluetoothLED
            │   ├── README.md
            │   ├── turtlebot3_core.ino
            │   ├── turtlebot3_core_config.h
            │   └── turtlebot3_waffle.h
            ├── subscriberLED
            │   ├── README.md
            │   ├── turtlebot3_core.ino
            │   ├── turtlebot3_core_config.h
            │   └── turtlebot3_waffle.h
            ├── turtlebot3_core.ino
            ├── turtlebot3_core_config.h
            └── turtlebot3_waffle.h

1. Motor Driver

this files are under the file lib/motor_driver. This is only for onExtraMotor/velocityMotor. Without this case, you can use default motor_driver.

• turtlebot3_motor_driver.cpp
• turtlebot3_motor_driver.h

2. Turelebot3 Core: Dynamixel

I modified turtlebot3_waffle's core to control more Dynamixel motors. If you upload this modified turtlebot core to OpenCR 1.0 using Arduino, you can control more extra motors and LED.

• turtlebot3_core.ino
• turtlebot3_core_config.h
• turtlebot3_waffle.h

There're two big directories.

• one extra motor: when you want to control one more motor (position mode / velocity mode)
• two extra motors: when you want to control two more motors (position mode)

2-1. One Extra Motor

• velocity mode: the motor should be velocity mode
• position mode: the motor should be position mode

2-2. Two Extra Motors

Two motors's mode should be position mode

• customVelocity: two motors start moving AT THE SAME SPEED simultaneously. This is why if their degree to move is different, their operations will not end moving at the same time. (same velocity)
• syncVelocity : two motors start moving AT THE COORDINATED SPEED simultaneously. two motors start and finish moving simultaneously, even though their degree to move is different. (different velocity)

> Compare customVelocity and syncVelocity

/	customVelocity	syncVelocity
mode	position	position
input	degree	degree
start time	same	same
end time	SAME	DIFFERENT
velocity	DIFFERENT	SAME

3. Turelebot3 Core: Dynamixel + LED

This code is from 'twoExtraMotors/syncVelocity'. OpenCR 1.0 would control two extra motors and 4 LED.

• turtlebot3_core.ino
• turtlebot3_core_config.h
• turtlebot3_waffle.h

There're two big directories.

• bluetoothLED: when you want to control two more motors (position mode) and LED using BLUETOOTH
• subscriberLED: when you want to control two more motors (position mode) and LED using SUBSCRIBER of ros topic

3-1. Control 4 LED using 'bluetooth'

• LED would be controlled by bluetooth. Connect to the terminal via Bluetooth.
  • If you send 'oo', you can turn on the LED
  • If you sent 'xx', you can turn off the LED
• Two motors's mode should be position mode
• LED and bluetooth module should be connected to OpenCR 1.0

3-2. Control 4 LED using 'subscriber' of ros topic

• LED would be controlled when topic '/blink_led'(msg: std_msgs/Byte).
  • When the robot moves forward, FRONT LED lights up (0b0001)
  • When the robot turns to the right, RIGHT LED lights up (0b0010)
  • When the robot moves backward, BACK LED lights up (0b0100)
  • When the robot turns to the left, LEFT LED lights up (0b1000)
  • When the robot control the module, ALL LED lights up (0b1111)
• Two motors's mode should be position mode
• LED should be connected to OpenCR 1.0

> Compare bluetoothLED and subscriberLED

Terminal	Robot	bluetoothLED	subscriberLED
aa	_	TURN ON
xx	_	TURN OFF
rr	_	RIGHT LED
ll	_	LEFT LED
ff	_	FRONT LED
bb	_	BACK LED
	move forward	_	FRONT LED
	move backward	_	BACK LED
	turn right	_	RIGHT LED
	turn left	_	LEFT LED
	control module	_	ALL